T. Holm — Studies in the Cyperacem. 303 



ent in the inflorescence of Cyperus, are, to some extent, also 

 observable in the panicle of certain Graminece. 



Among the species of Oyperus, in which the inflorescence is 

 ample and in which all the foliar organs are well developed 

 and easily distinguishable, C. phymatodes Muehl. may be used 

 for illustrating the composition. The accompanying figure 1 

 represents the upper part of the flower-bearing stem (St.) with 

 the long, leafy bracts (B 1 ) arranged in a whorl near the apex 

 and supporting secondary branches or rays, as they are often 

 called (R 2 ), each of which bears a tubular prophyllon or fore- 

 leaf (P 1 ) at the base. 



The flower-bearing stem itself is terminated by a spike (8), 

 borne on a similar ray (R 1 ) with several lateral spikes besides, but 

 of course destitute of any bract or fore-leaf, since it is terminal. 

 Each of the axillary rays (R 2 ) bears one pair of nearly opposite 

 rays (R 3 ), subtended by very small bracts (B 2 ) and provided 

 with minute fore-leaves (P 2 ) ; above these secondary rays (R 3 ) 

 there is a number of sessile spikes, of which the uppermost is 

 the terminal. By examining these sessile spikes, magnified in 

 our figure 3, it is readily seen that with the exception of the 

 terminal, they are subtended by small bracts (B 2 ) and that each 

 spike bears a fore-leaf (P 2 ); moreover this same manner of 

 ramification becomes repeated in the minor inflorescence of 

 third order where the branch (R 3 ) with its bract (B 2 ) and fore- 

 leaf (P 2 ) bears some spikes of third order each with a small 

 bract (B s ) and a fore-leaf (P s ) at the base. — The flower-bearing 

 stem (St. in fig. 1.) is, thus, extended into a short and slender 

 rhachis (R 1 ) above the involucral leaves (B 1 ) and this rhachis 

 or ray (R 1 ) is terminated by a sessile spike (S), overtopping a 

 various number of scattered, sessile and simple spikes, all of 

 which are lateral, being developed from the axils of small bracts, 

 and each bearing a minute fore-leaf at the base. The only 

 difference between this terminal inflorescence (R 1 — S) and the 

 larger, lateral ones depends, thus, merely upon these being sup- 

 ported by bracts (B 1 ) and by the presence of fore-leaves (P 1 ) ; 

 these fore-leaves (fig. 2.) correspond to the so-called clado- 

 prophylla, which we have described in a paper upon Carex* 



This type of umbellate inflorescence is characteristic of 

 several other genera within the order, and is w T ell represented 

 in certain species of Sciipus, Eriophorum, Fimbristylis, etc. 

 It is, moreover, to be found in Dulic/dum, but with the differ- 

 ence that in this genus the inflorescence, although composed 

 of exactly the same organs, is very long, the internodes between 

 the leaves, which subtend the lateral rays, being developed as 

 distinct internodes, and the subtending leaves being provided 

 * This Journal, vol. ii, p. 214, 1896. 



